To answer the main question I'd say no, I don't think it's underwhelming.
It's much better than the previous (current) gen of PS3/360 and I'm happy about it. I myself completely skipped the 360 and PS3, and only bought a Wii about a year ago. I played (and still occasionally do) games on my cousin's 360 when I go at his place and we rent games for the heck of it but that's about it. The only thing that I don't like is the XBOX One's name and look. I never liked "XBOX" to start with, but XBOX One is bad, but even worse than the name (when I thought that Nintendo's Wii couldn't be beaten) is the look. It doesn't even look like a "video game console". I think Microsoft probably went something along the lines of "hell Nintendo got away with making a cube, let's make a rectangle!". Yeah great idea MS, keep at it.
But anyway, beyond the terribad design and its name, it's alright, as long as it's better than the current gen it should hold its ground for the next couple of years until, once more, history repeats itself. I'm just happy we'll finally get to effectively move on to another gen (rather than saying the "next gen", because saying "next gen" implies it should be leaps and bounds ahead, and in reality it ain't the case, it's just "another gen", but that's ok by itself).
For the "next gen" I will probably buy a PS4, 'cause the XBOX One is so damn ugly and I don't want to look at a VHS player below or next to my HDTV (nah, joking, partly, it does look bad but I still wouldn't buy one even if it looked better, I'm just not interested at all by the XBOX One so far). But in reality I will probably stick with my Wii, maybe will buy a Wii U much later on (like in two or three years from now) and that might be it, because in the end I'm mostly a PC gamer and I nkow that most PS4 games I'd buy will end up ported to PC anyway (in which case, hopefully, we'll have more video/audio options along with the possibility to mod them as well).
To be honest though I have this feeling that this "next gen" we'll get is going to be the last gen of "video games consoles" (heck that was probably over anyway with the 360 and PS3). The following gen, in maybe six, seven or eight years from now, what could it possibly be beyond being faster hardware-wise? They're more like "complete entertainment systems" now rather than being built up to "only play video games". We can watch movies, go on the web and I'm sure the XBOX One will get its peripheral so that we can make our toasts for breakfast with the damn thing (I mean seriously). I'm sure at some point we'll get some APP allowing us to order our pizza by calling our local pizzeria via our PS4 with voice recognition and a couple of controller button pushes. It's getting ridiculous if you ask me but that's probably because I'm getting too old.
But... yeah back on track, I think that spec-wise they're alright, could have been better but then again everything can always be better so yeah.